diff --git a/.github/workflows/docker-image.yml b/.github/workflows/docker-image.yml
index ba63d7ed..a884cf22 100644
--- a/.github/workflows/docker-image.yml
+++ b/.github/workflows/docker-image.yml
@@ -27,5 +27,7 @@ jobs:
     - name: Push image
       run: |
         IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
+        # repository name must be lowercase
+        IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
         docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
         docker push $IMAGE_ID:$VERSION